Machine for grinding the main bearing pins and crankpins of crankshafts



R. MUSYL MACHINE FOR GRINDING THE MAIN BEARING May 20, 1952 PINS AND CRANK PINS OF CRANKSHAFTS 4 Sheets-Sheet 1 Filed May 28, 1949 INVENTOR:

L K vr 5 WW O N T RA MK 0 R y 20, 1952 R. MUSYL MACHINE FOR GRINDING THE MAIN BEARING PINS AND CRANK PINS OF CRANKSHAFTS Filed May 28, 1949 4 Sheets-Sheet 2 25 23 27 Fig.4

IN V EN TOR.- R085 R T MUS FL KAW ATTOR EK May 20, 1952 R. MUSYL 2,597,167

MACHINE FOR GRINDING THE MAIN BEARING PINS AND CRANK PINS 0F CRANKSHAFTS Filed May 28, 1949 4 Sheets-Sheet.;-

Fig.7

IN V EN TOR:

ROBER T MUS VL BY WNW ATTORN K MUSYL MACHINE FOR GRINDING THE MAIN BEARING PINS AND CRANK PINS OF CRANKSHAFTS Filed May 28, 1949 May 20, 1952 4 Sheets-SheetA INVENTOR: ROBER T MUSVL ATTOPNE Patented May 20 1952 MACHINE. FOR GRINDING THE MAIN BEAR- ING ?INS' AND CRANKPINS 9F CRANK- SHAFTS Robert Musyl, Vienna, Austria Application May 28, 1949, Serial No. 96,096- In Austria June 10, 1948 i-Claims. (oi. 51-9ii) corresponding to the eccentric movement of the pinbeing ground has been proposed heretofore. However, in this case the oscillatory motion of the grinding wheel is derived in direct fashion fromthe crank pin being ground, which results in anumber of disadvantages. The greatest drawback resides in the oscillatory and accordingly' the irregular motion of the grinding wheel, which produce forces of inertia, which are incapable of being compensated and limit the rate andaccuracy of the operation. A further disadvantage resides in the direct copying of the oscillatory' motion of the grinding wheel from the crank pin being ground, whereby there occurs during. the operation a considerable and above all, owing to the changing forces of inertia, variable-deformation of the piece of work. A third disadvantage of the known apparatus consists in thefact that owing to derivation of the oscillatorymotion of the tool in the copying process from the crank pin being ground an initially oval pin: admittedly acquires a round form by corresponding arrangement of the copying device, but the position of its-centre after completion of the grinding operation depends solely on the form of the pin prior to the initial treatment and cannot be variedby adjustment of the machine. Rectificationofthe centre of a pin which was incorrect prior to the grinding is accordingly impossible.

The-known apparatus does, therefore, not satisfytherequirements of series production either as regards the circumferential velocity, and accordingly the output, or as regards accuracy, and is, therefore, employed solelyas a machine for carrying out repair Work.

A machine according to the invention for grinding the main bearing pins and crank pins of crankshafts comprises at least one grinding wheel, a support for said grinding wheel, means for rotating acrankshaft to be ground, during the grinding thereof, about the longitudinal axes of the main bearing pins of said crankshaft, and means for impartingto the axis of said grinding wheel a; movement congruent to that of a crank pin or main bearing pin to be ground when the respective crankshaft is mounted in the machine to rotate about the said longitudinal axes.

This machine therefore, completely avoidsthe disadvantages above referred to. The masses of the grinding device, rotating according to the invention in even fashion, can be wholly compensated without difficulty. The control movement is not derived from the piece of work, so that mutual interference between-tool and piece of work cannot occur. Finally, owing to adjustability both of the phase position as well as the eccentricity oi the centre of the grinding spindle without a break, any desired middle position of the crank pin to ,be ground can be obtained independently of its form and position prior to the grinding operation.

The arrangement according to the invention also results in a number of important advantages as compared with grinding machines having a stationary grinding-wheel centre point, which was the only grinding machine employed heretofore for the series production of crankshafts. Owing to the central location of the piece of work in the machine the device hithertounavoidable for the purpose of positioning thecan be employed. Further, the double-ended actuation of the piece of work heretofore necessary in the case of eccentric location in the machine in order to avoid deformation due to the driving movement may be dispensed with, whereby the design of the grinding machine is simplified and its total weight is reduced. The main advantage of the apparatus according to the invention is, however, the possibility of working on a plurality of or all bearing points of a crankshaft, whether main bearings or crank pins simultaneously in one operation.

If furthermore as indicated in the following example, the machine is furnished with two' bed plates disposed on the same level and movable selectively into the operative position, it is possible during the grinding of a piece of work the check up in the clamping position on a second for working on the crank pins of a crankshaft 3 having four throws to less than one quarter as compared with the known machines.

In order that the invention may be more readily understood, preferred embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which Fig. 1 illustrates the principle of operation of a machine according to the invention.

Fig. 2 is a diagram of control in respect of the movement of the grinding wheels.

Figs. 3 and 4 illustrate in side view and partial longitudinal section respectively a modified embodiment of the drive and the mounting of the grinding wheel.

Figs. 5 and 6 show in longitudinal section and side view respectively the method of compensating the eccentrically rotating weight of the grinding wheel.

Figs. 7 and 8 and 9- show in front elevation, plan and side elevation respectively a grinding machine of the single-spindle type, and

Figs. 10, 11 and 12 are similar views, showing a four-spindle arrangement for grinding the crank pins of a four-throw crankshaft.

According to Fig. 1, the crankshaft to be ground is rotated at even circumferential velocity about its central axis I in the direction of the arrow. The crank webs are designated 2, whilst the crank pin to be worked upon by the grinding wheel 4 is designated 3. In addition to the extreme front position of the crank pin 3 and the grinding wheel 4 shown in full lines there are shown in dotted lines two further positions which are reached upon rotation of the piece of work by 120 and 240 respectively.

The grinding wheel spindle 5 is driven by way of a belt by a motor not shown in Fig. 1. It is eccentrically mounted, with an eccentricity er, in an eccentric sleeve 6, which in turn is mounted, with an eccentricity ea in the drum 1, which is rotatably mounted in the grinding wheel support. The total eccentricity e of the grinding wheel spindle is accordingly the geometric total of the part-eccentricities er and e2. If these are made to be exactly the same (81 62), the total eccentricity 6 can be varied without a break from e1e2:0 to e1+ez:2e1 by rotation of the eccentric sleeve 6 in the drum 1. The total eccentricity is so adjusted in a manner to be described later that it is equal to the eccentricity of the crank pin to be ground. The drum 1 runs synchronously and in equal phase with the crank pin to be ground, which is accordingly acted upon with the adjusted eccentricity and phase'position. The diameter of the treatment is determined by adjusting the grinding wheel support in a line connecting the centre of the drum l with that of the workpiece I.

Fig. 2 shows the drive for the control movement of the grinding wheel. The references I to l and also e1, e2 and e correspond to Fig. 1. Fig. 2 furthermore shows the motor, mounted in the grinding wheel support, for the control movement, which motor is coupled electrically or mechanically with the exactly synchronously running drive for the piece of work. It drives the drum 1, rotatably mounted in the support l3, by way of a pinion 9 and spur wheel [0. The same figure shows the arrangement for unbroken adjustment of the eccentricity of the grinding spindle. This adjustment takes place by relative rotation of the eccentric sleeve 6 and the drum 7, which during the grinding operation are locked in relation to one another. In order to ensure that this adjustment will take place without variation of the phase position of the resulting eccentricity e, the eccentric sleeve 6 and the drum 1 are coupled together by a planetwheel gear l5, l1, l8 and I9. If the wheel [6 of the planet gear having the inner teeth is blocked by means of the locking pin [2 and the externally disposed latching device, 1. e. the latching teeth II, in the grinding wheel support 13, and the drum 1, the control drive 8 being disengaged and the locking between the eccentric sleeve 6 and the drum 1 disconnected, is rotated by way of the hand wheel [4 and the pinion [5, the gear wheel ll will move over the stationary inner teeth It and cause by way of the intermediate wheel l8 and the teeth 19 a rotation of the cocentric sleeve 6 in the opposite direction and by twice the angle. Since, as already set forth, the eccentricities er and e2 are equal, the direction of the resulting eccentricity remains on the basis of adherence to geometric laws unchanged.

When the desired eccentricity has been adjusted, the blocking device, not shown, between the eccentric sleeve 6 and the drum 1 is made to engage, and the latching pin [2 is released. By actuating of the hand wheel l4 whilst the control drive 8 and 9 is still disconnected the drum I can now be rotated in relation to the piece of work, whilst the eccentricity remains the same, and the phase position adjusted. When this adjustment has also been made the hand drive [4 and I5 is disconnected by means of a clutch, which operates without play, and the control motor drive 8 and 5 is connected, the apparatus then being ready for operation. operation of the work and of the drum 1 may be effected mechanically by the provision of a bevel gear wheel 50 on the main drive shaft 5| for the grinding wheel 4. Gear wheel 50 meshes with a bevel gear wheel 52 at the end of a splined shaft 53. The latter extends axially slidably into a corresponding female end portion of a shaft 54 on whose far end a bevel gear wheel 55 is fixed. The latter meshes with a bevel gear wheel 56 on the drive shaft for the work, i. e. the crank shaft I, 2, 3. The transmission ratio between wheel 59 and wheel 56 is 1:1. The telescope connection between shafts 53 and 54 permits the use of the device for working crankshafts of different shaft diameters. The grinding wheel support I3 is displaceable from and toward the work piece in the conventional manner. Mechanism 50 to 56 is shown in dotted lines in Fig. 2 because the mechanism may be disposed in a plane in front or in the rear of the plane of Fig. 2..

Fig. 3 is a longitudinal section through the grinding wheel spindle mounting, showing the grinding wheel spindle 5, the eccentric sleeve 6 and the drum 1, together with the bearings Zll and 2| therefor in the grinding wheel support [3 (Fig. 2). There are also shown in Fig. 3 the driving belt pulley 26 for the grinding wheel 4. and the driving belt 24.

Fig. 4 is a side elevation of the grinding wheel drive, the references I to l agreeing with the preceding figures. The driving motor 22 is firmly mounted on the grinding wheel support l3 (Fig. 2), and accordingly does not participate in the control movement of the grinding wheel 4. The power transmission from the stationary motor to the grinding wheel spindle 5 rotating synchronously with the crank pins 3 to be ground takes place by way of two belt drives 23 and 24. The driving belt pulley 25 is mounted on the mo- Synchronous tion, an eccentric gear unit, a grinding wheel shaft rotatably and eccentrically supported by said unit, a rotatable mountin for a work piece, means to rotate said grinding wheel shaft, variable effect suspension means connected with said shaft and comprising resilient means for varying the suspensive effect of said suspension means for compensating the gravity effect of the rotating masses while said shaft is moved parallel to itself by said unit.

7. A grinding machine as defined in claim 6, comprising adjusting means connected with said suspension means for adjusting the tension of said resilient means.

8. A grinding machine comprising, in combination, an eccentric gear unit, a grinding wheel shaft rotatably and eccentrically supported by said unit, a rotatable mounting for a work piece, means to rotate said grinding wheel shaft, suspension means connected with said shaft and comprising means for varying the suspensive effect for compensating the gravity effect of the rotating masses while said shaft is moved parallel to itself by said unit, said suspension means comprising a rocker member having one end rotatably connected with said shaft, a bell crank lever means swingable on a stationary fulcrum and having one arm movably connected with the other end of said member, and a spring having a fixed end an an end connected with the other arm of said lever means.

9. A grinding machine as defined in claim 8, the point of connection of said spring with the other arm of said lever means being adjustably movable towards and from the fulcrum of said lever means for adjusting the effect of said spring on said suspension means.

10. A grinding machine comprising, in combination, an eccentric gear unit, a grinding wheel rotatably and eccentrically supported by said unit, a rotatable mounting for a work piece, drive means to rotate the said mounting, drive means to rotate said unit, disconnectable synchronizing means affording synchronized operation of both drive means and temporary suspension of such operation, and means independent of said drive means to rotate said grinding wheel.

11. A grinding machine comprising, in combination, an eccentric gear unit, a grinding wheel shaft rotatably and eccentrically supported by said unit, a rotatable mounting for a work piece, means to rotate the said mounting, means synchronized with said last mentioned means to rotate said unit, drive means to rotate said grinding wheel shaft, said drive means comprising a shaft rotating on a stationary axis, a link member swingably supported by said grinding wheel shaft, an arm member swingable on said shaft which rotates on a stationary axis, a pin swingably interconnecting said link member and said arm member, a pulley on said pin, flexible means drivingly connecting said shaft rotating on a stationary axis and said pulley, and a second flexible means drivingly connecting said pulley with said grinding wheel shaft;

12. A grinding machine comprising, in combination, a plurality of individual grinding units, each unit having an eccentric gear having horizontal rotation axes, a grinding wheel rotatably and eccentrically supported by said eccentric gear, and means to rotate said grinding wheel; a mounting for a work piece rotating on a horizontal axis, means to rotate said mounting, means synchronized "with said last mentioned means to rotate said eccentric gears; and a machine bed supporting said units in a row.

13. A grinding machine comprising, in combination, a plurality of individual grinding units, each unit having an eccentric gear having horizontal rotation axes, a grinding wheel rotatably and eccentrically supported by said eccentric gear, and means to rotate said grinding wheel; a mounting for a work piece rotating on a horizontal axis, means to rotate said mounting, means synchronized with said last mentioned means to rotate said eccentric gears; and a machine bed supporting a number of said units on one side and the other units on the other side of the rotation axis of said rotatable mounting.

14. An external grindin machine particularly for crankshafts comprising, in combination, a plurality of individual grinding units, each unit comprisin an eccentric gear, a grinding wheel rotatably and eccentrically supported by said gear, drive means for said gear, and means to rotate said grinding wheel; a. plurality of mountings for work pieces rotating on a horizontal axis, means synchronized with said drive means to rotate said mountings, and a machine bed (:0- axially supporting said mountings.

15. An external grinding machine particularly for crankshafts comprising, in combination, a plurality of individual grinding units, each unit comprisin an eccentric gear, a grinding wheel rotatably and eccentrically supported by said gear, drive means for said gear, and means to 1'0- tate said grinding wheel; a plurality of mountings for work pieces rotating on a horizontal axis, means synchronized with said drive means to rotate said mountings, and a machine bed coaxially and axially displaceably supporting said mountings.

ROBERT MUSYL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,361,850 Guild Dec. 14, 1920 1,728,653 Baumberger Sept. 17, 1929 1,926,779 Law Sept. 12, 1933 2,012,263 Amidon Aug. 27, 1935 2,232,228 Groene Feb. 18, 1941 2,232,229 Groene Feb. 18, 1941 FOREIGN PATENTS Number Country Date 670,342 Germany Jan. 17, 1939 

